title: Histopathological evaluation of different methods of experimental induction of periapical periodontitis.
abstract: This study evaluated histopathologically different methods of experimental induction of periapical periodontitis. The radiographic and microbiological evaluations have been performed in a previous investigation. Fifty-seven root canals from dogs' teeth were assigned to 4 groups. In GI (n=14) and GII (n=14), the root canals were exposed to oral environment for 180 days; in GIII (n=14) and GIV (n=15) the root canals were exposed for 7 days and then the access cavities were restored and remained sealed for 53 days. The root apices of GI and GIII were perforated, whilst those of GII and GIV remained intact. After induction of periapical periodontitis, the dogs were euthanized. Serial sections were obtained and stained with hematoxylin and eosin. Data of the histopathological evaluation were submitted to Kruskal-Wallis and Dunn's tests at 5% significance level. The inflammatory periapical reaction and resorption of mineralized tissues were less intense in GII than in the other groups (p<0.05). There was no histopathological difference among the experimentally induced periapical lesions in the teeth with coronal sealing. On the other hand, when coronal sealing was not performed, greater intensity of induced periapical periodontitis was observed in the teeth with apical perforation.
authors.affiliation: Department of Restorative Dentistry, Dental School of Araraquara, São Paulo State University, Araraquara, SP, Brazil.
authors.forename: Juliane Maria Guerreiro
authors.initials: JM
authors.lastname: Tanomaru
authors.forename: Mario Roberto
authors.initials: MR
authors.lastname: Leonardo
authors.forename: Léa Assed Bezerra
authors.initials: LA
authors.lastname: Silva
authors.forename: Angelo
authors.initials: A
authors.lastname: Poliseli-Neto
authors.forename: Mário
authors.initials: M
authors.lastname: Tanomaru-Filho
mesh_terms: D016301:Alveolar Bone Loss / Q000209:etiology / Q000473:pathology; D000818:Animals; D001641:Bicuspid / Q000473:pathology / Q000601:surgery; D003739:Dental Cementum / Q000473:pathology; D003786:Dental Pulp Cavity / Q000473:pathology; D003804:Dentin / Q000473:pathology; D004195:Disease Models, Animal; D004285:Dogs; D007249:Inflammation; D007963:Leukocytes, Mononuclear / Q000473:pathology; D009336:Necrosis; D010485:Periapical Periodontitis / Q000209:etiology* / Q000473:pathology; D010513:Periodontal Ligament / Q000473:pathology; D011670:Pulpectomy; D012389:Root Canal Obturation; D018915:Root Canal Preparation; D012391:Root Resorption / Q000209:etiology / Q000473:pathology; D013997:Time Factors; D019227:Tooth Apex / Q000293:injuries / Q000473:pathology